Lysol Ineffective

Listen up, buttercup. This joke is saying you're such a nasty germ that even Lysol, which kills almost all germs, couldn't finish the job. In fact, you're in the 0.01% that survived. You may not know this, but you should, as a testament to how dumb you are, Lysol is a disinfectant used to kill germs and bacteria. The joke is suggesting that the person being spoken to is so disgusting that they're among the few germs resistant to Lysol.